1. Field of the Invention
The present invention relates to a polyphenylene ether copolymer and thermoplastic resin compositions containing said copolymer. The copolymer and compositions are excellent in heat resistance, thermal stability, mechanical strength, moldability and solvent resistance.
2. Prior Art
Polyphenylene ether resins are excellent in heat resistance, mechanical strength, electrical characteristics, dimensional stability and water resistance, but are disadvantageous in that they are poor in solvent resistance and molding processability.
As a means for improving the solvent resistance and molding processability of a polyphenylene ether, various attempts have been made to blend a polyolefin with the polyphenylene ether.
However, in the case of mixing a polyphenylene ether resin and a polyolefin resin proposed by Jap. Pat. Pub. No. SHO 42 (1967)-7069, since the compatibility between the polyphenylene ether and the polyolefin is poor, addition of a large amount of the polyolefin causes exfoliation in a molded product obtained from the resins. In the case of a resin composition comprising a polyphenylene ether, a polyolefin and a partially hydrogenated alkenyl aromatic compound-conjugated diene block copolymer, which has been proposed by Jap. Pat. Appln. Kokai (Laid-Open) No. SHO 63 (1988)-83149, and a resin molded product obtained using a polyphenylene ether as a continuous phase and dispersing at least one copolymer having a specified particle size and selected from the group consisting of vinyl aromatic compound-conjugated diene compound copolymers and hydrogenated products thereof in a polyolefin outer layer, which has been proposed by Jap. Pat. Appln. No. SHO 63 (1988)-276314 (WO 9105016), they are disadvantageous in that they do not have heat resistance sufficient to contain the alkenyl aromatic compound and they form a flow mark under severe molding conditions.
A composition comprising a polyolefin having a glycidyl group and a polyphenylene ether proposed by Jap. Pat. Appln. Kokai (Laid-Open) No. SHO 61 (1986)-53355 does not have sufficiently improved mechanical strength and heat resistance. Jap. Pat. Appln. Kokai (Laid-Open) No. SHO 63 (1985)-1289056 (U.S. Pat. No. 4914153 and EP 268486) discloses a resin composition comprising a polyphenylene ether modified with an acid anhydride, a polyolefin modified with glycidyl methacrylate or the like and a vinyl or vinylidene compound, and a binder such as diamine. However, although this composition has somewhat improved mechanical strength and solvent resistance, it is insufficient in heat resistance because the modified polyolefin contains, for example, styrene as an essential constituent.
Jap. Pat Appln. Kokai (Laid-Open) No. HEI 2 (1990)-173137 has proposed a resin composition comprising a polyphenylene ether, a modified polyolfin containing an amino group, a polar-group-containing polyphenylene ether, and a polyolefin. However, a molded product obtained from this composition is not sufficient in mechanical strength.
Jap. Offic. Pat. Gaz. No. HEI 2 (1990)-500283 (WO 8808433) discloses a composition comprising a reaction product of a polyphenylene ether with a substituted olefin having a functional group, and a polyolefin reactive therewith. However, this composition does not have sufficient mechanical strength.